Shifting device for teleprinters



g- 22, 1967 RENTARO SASAKI SHIFTING DEVICE FOR TELEPRINTERS 2 Sheets-Sheet 1 Filed Oct. 20, 1965 INVENTOR REA/T490 $434K! ATTORNEYS g- 22, 6 RENTARO SASAKI SHIFTING DEVICE FOR TELEPRINTE'RS 2 Sheets-Sheet 2 Filed Oct. 20, 1965 INVENTOR RENTAPO 5454/ ATTORNEYS United States Patent Ofi 3,337,019 Patented Aug. 22, 1967 ice 3,337,019 SHIFTING DEVICE FOR TELEPRINTERS Rentaro Sasaki, 2947-1 Ishiharacho, Takasaki, Gunma Prefecture, Japan Filed Oct. 20, 1965, Ser. No. 498,657 Claims priority, application Japan, Dec. 11, 1964, 39/ 95,159 6 Claims. (Cl. 197-18) This invention relates to a shifting device for the printing drums of teleprinters.

In accordance with the invention, a printing drum, carrying a plurality of types or character blocks, is divided circumferentially into a plurality of equal sectors.

rality or radially extending arms equal in number to the number of printing drum sectors, and these radially extending arms are at equal angular distances from each other or, in other words, are uniformly spaced angularly around the selecting shaft.

Driving means are provided to rotate the shaft through engagement with one of the mentioned arms, and this rotation of the shaft brings the driven arm into a position whereby, upon retraction of the driving means, the selected arm may be locked to lock the selecting shaft against movement. In turn, this driving adjusts the printing drum to .the proper angular position to bring the selected sector, and the type thereon, into operative printing position. Additional means, preferably including differential or planetary gearing means, are provided for further rotating the drum to bring into the operative printing position selected type within the selected printing drum sector.

An object of the present invention is to provide a shifting device for a teleprinter printing drum which can easily adapt to variations in the number of selecting positions.

Another object of the present invention is to provide a shifting device for a teleprinter which is simple in the structure.

In the accompanying drawings;

FIGURE 1 is a perspective view of a shifting device embodying the present invention.

FIG. 2 is an end elevation View of the type drum shown in FIG. 1; and

FIGS. 3A through 3E are elevation views of the arm driving and locking means illustrating different stages of the selecting operation.

The accompanying drawings show a device according to the present invention as applied to a three-step shifting mechanism. Referring to the drawings, three selector magnets 1a, 1b and 1c are provided, each having a pivoted armature 2a, 2b and 2c, respectively, associated therewith. These pivoted armatures act as latches which, when the selector magnets are not energized, maintain selector pawls 3a, 3b and 3c in the position shown in the drawing. Whenever a selector magnet 1a, lb or 10 is energized, its armature 2a, 2b or 20, respectively, is drawn down to release the associated pawl 3a, 315 or 3c, respectively. The released pawl is then in a position to be engaged by a draw bar 4 having a bent end engageable with the down turned end of the released pawl. Draw bar 4 has its other end pivotally connected to a V-shaped lever 7 which carries a roller 6 engaged wit-h a cam 5, roller 6 being biased into engagement with cam by a tension spring 9. When cam 5 is rotated through one revolution, arm 7 is first swung clockwise and then swung counterclockwise. This draws the released pawl to the right, and then the pawl returns to the left under the influence of a tension spring secured between an end thereof and an associated pivoted lever 8a, 8b or 80. Consequently, the pivoted lever 8a, 817 or 8c operatively associated with the released pawl is first swung clockwise and then returned counterclockwise under the influence of tension springs 20a, 20b and 200 each associated with one of the pivoted levers 8a, 8b and 80, respectively.

There is provided a bank of selecting for-ks 10a, 10b and 101: which are equal in number to the number of selector magnets 1a, 1b and 1c, and each selecting fork has operatively engaged therewith the upper end of one of the selecting levers so that, upon clockwise movement of the associated selecting lever 8a, 8b or 80, the associated selecting fork 10a, 10b or 100, respectively, is moved to the right and, when the associated selecting lever is drawn back to the left by the tension springs 20a, 20b or 20c, the corresponding selecting fork is also withdrawn.

The three selecting forks, corresponding in number to the selector magnets, are substantially rectangular forks including a pair of legs extending at right angles to a base. The base of each of the selector forks is formed with an elongated recess, such as the recesses 18a and 18b, and each of these recesses is arranged to receive, under certain circumstances, the major portion of a selector arm 15, 16 or 17 as will be described more fully hereinafter. The legs of the selector forks are engaged with, or abut, the ends of the legs of a substantially rectangular-shaped channel locking slide 1.1 which is biased to the left, as indicated in the drawings, by compression springs 12, so that locking slide 11 will follow the movement of any selector fork which is displaced by its associated selector lever. The base of locking slide 11 has a rectangular finger extending centrally from its inner end and substantially aligned with the recesses 18a, 1812, etc.

A shift selecting shaft 14a extends into the open rectangular area defined by the bank of selector levers and the locking slide, and the end of shaft 14a extending into this open rectangular area has secured thereto the three selector arms 15, 16 and 17. These arms extend radially from the shift selecting shaft 14a and are arranged at uniform angular spacings around the shaft, the angular spacing, in the illustrated embodiment, being inasmuch as there are three selector arms each corresponding to one of three selecting positions as determined by the selector magnets 1a, 1b and 10. Each selector arm 15, 16 or 17 is substantially coplanar with a respective selector fork 10a, 10b or 100, and each selector arm has its outer end formed with a rectangular notch which is arranged to have a conforming engagement with the rectangular finger 13 on the slide 11. The opposite end of shaft 14a carries a bevel gear 23, and shaft 14a is coaxial with the main portion of a selecting shaft 14b whose end adjacent shaft 14a is bent at right angles and carries a bevel gear 24 meshing with the bevel gear 23. Bevel gear 24 furthermore meshes with a bevel gear 25 fixed to shaft 14b. The shaft 14b also carries a pinion 26 which meshes with a rack 27.

Shaft 14b is secured to rotate with a type drum 19 which, as shown in FIG. 2, includes three equal shift sectors 19a, 19b and 19c corresponding to the selector arms 15, 16 and 17, respectively. The type or character blocks on drum 19 is distributed between the three equal sectors thereof. Drum 19 is associated with a cylindrical platen 21 which feeds paper 22 into a position for printing cooperation with drum 19.

FIG. 1 illustrates the position of the parts wherein the type sector of drum 19 has been selected and is in the printing position with respect to platen 21 and aper 22. In this case, the corresponding selector arm 7 has its rectangular recess engaged with the rectangular nger of slide 11. Starting from this position, it will now e explained how the type sector 19a is selected to be perative.

To select type sector 19a, selector electromagnet 1a energized drawing down its armature 2a and releasing be associated pawl 3a to pivot clockwise. Pawl 3a may hus be engaged by draw' bar 4. Cam 5 is now rotated .nd, during such rotation, draw bar 4 is pulled to the ight by clockwise movement of lever 7 effected by cam ollower 6 engaged with cam 5. This swings selector ever 8a clockwise moving selector fork 10a to the right 1nd displacing locking slide 11 to the right to release inger 17 from finger 13, so that shaft 14a can be rotated. As selector fork 10a moves to the right from the position lhOWIl in FIG. 3A to that shown in FIG. 3B, it engages inger 15 and, as further shown in FIGS. 30 and 3D, it 'otates finger 15, and thus shaft 14a, clockwise with the nub portion of finger 15 eventually entering the recess 18a of selector fork 10a. The consequent rotation of shaft 14a rotates bevel gear 23 which, through planetary bevel gear 24, rotates bevel gear 25 and thus shaft 14b to rotate drum 19 to a position wherein the type sector 19a is in operative printing position.

Selector magnet 1a is then deenergized, so that pawl 3a is disengaged from draw bar 44 and is returned, together with lever 8a, to the left under the influence of tension spring 20a. Selecting fork 10a and locking slide 11 are also returned to the position shown in FIG. 1 and which corresponds to the position shown in FIG. 3E. During this return, finger 13 of slide 11 engages in the outwardly opening rectangular notch in the free end of selector arm 15, thus locking shaft 14a in its angularly adjusted position.

The next step is the selection of the particular types 1911 -1901 in the shift sector 1%. As just-mentioned, the shift sector has already been selected and it is now necessary to select the particular types within the shift sector. To effect this latter, a conventional type selecting mechanism, which has not been illustrated, displaces rack 27 and this rotates pinion 26. The conjoint rotation of shaft 14b and drum 19 relative to shaft 14a is made possible due to the planetary pinion 24 engaged between bevel gears 23 and 25. Thus, the fine selection of the type is made. In effect, the total angular displacement of shaft 14b and drum 19 is a combination of the displacement of shaft 14a through operation of the selector fork 10a and selector finger 15 and the additional rotation of shaft 14b effected by movement of rack 27 engaged with pinion 26.

The shifting device according to the present invention is. not limited to the embodiment described above. Thus, for example, by fitting it to a platen shaft, a quick fixed line shifting operation can be also attained.

What is claimed is:

1. A shifting device for a teleprinter comprising, in combination, a type drum having a type carrying surface divided circumferentially into a plurality of zones of equal angular extent, with the type being distributed among said zones; shaft means operable to displace said drum angularly to bring a selected zone into an operative printing position; a plurality of selector arms, equal in number to. said zones, extending radially from said shaft means at equal angular spacings corresponding to the angular extents of said zones; and each coordinated with a respective zone; a plurality of selector forks reciprocable transversely of said shaft means and each aligned with and at least partially embracing a respective selector arm; locking slide means disposed in opposition to said selector forks and relative to said shaft means; means biasing said locking slide means towards said shaft means and into locking engagement with the selector arm then in the latching position; each selector fork, when moved towards said shaft means, displacing said locking slide 4 means out of said locking engagement and engaging its associated selector arm and rotating it, together with said shaft means, to a latching position in which the associated zone is in said operative printing position; and selector means operable, when activated, to move a selected selector fork towards said shaft means and then to retract it; eachselector fork, upon such retraction, releasing said locking slide means to move into such locking engagement.

2. A shifting device for a teleprinter, as claimed in claim 1, including type selector means operatively associated with said shaft means and operable to effect a further angular displacement of said drum within the angular extent of the selected zone, to move a selected type within the selected zone into the operative printing position.

3. A shifting device for a teleprinter, as claimed in claim 2, in which said shaft means includes a first shaft having said selector arms extending radially therefrom and a second shaft, coaxial with said first shaft, and secured to said drum; differential gearing interconnecting said first and second shafts for conjoint rotation responsive to rotation of a selector arm by the associated selector fork; said type selector means being operatively connected to said second shaft to displace the same angularly relative to said first shaft, said differential gearing providing for such relative angular displacement when said first shaft is locked by engagement of said locking slide means with the selector arm then in the latching position.

4. A shifting device for a teleprinter, as claimed in claim 3, in which said first and second shafts have ends in opposition, the opposing end of each shaft carrying a bevel gear facing the bevel gear on the other shaft; said second shaft having its end bent at right angles to its major axis to extend between said bevel gears; and a third bevel gear rotatably mounted on said bent end and engaged with both of said first mentioned bevel gears; said bevel gears constituting said differential gearing.

5. A shifting device for a teleprinter, as claimed in claim 1, in which each selector fork has a substantially rectangular U-shape including a pair of arms extending at right angles from a base; said base having an elongated recess formed therein in alignment with said shaft means and conformingly receiving the associated selector arm when the latter is in said latching position.

6. A shifting device for a teleprinter, as claimed in claim 5, in which said locking slide means comprises a substantially rectangular U-shape locking slide including a pair of arms extending at right angles to a base, the arms being engageable with the arms of said selector forks; said slide including a substantially rectangular finger extending centrally from its base towards said shaft means; each of said selector arms being formed with a substantially rectangular notch in its free end and engageable with said substantially rectangular finger in the latching position of the selector arm.

References Cited UNITED STATES PATENTS 239,323 4/1331 McKittrick 197-13 667,433 2/1901 Ferguson 197-13 X 920,651 4/1909 Richards "197-13 2,023,949 12/1935 Cammen 198-34 2,365,913 12/1944 Stenfors 197-13 3,144,320 8/1964 Wales 197-13 X OTHER REFERENCES Article entitled Keyboard and Print Wheel Entry, by C. A. Foot in the IBM Technical Disclosure Bulletin, volume 5, No. 2, July 1962. Page 31 relied upon.

WILLIAM B. PENN, Primary Examiner.

ROBERT E. PULFREY, Examiner.

E. S. BURR, Assistant Examiner. 

1. A SHIFTING DEVICE FOR A TELEPRINTER COMPRISING, IN COMBINATION, A TYPE DRUM HAVING A TYPE CARRYING SURFACE DIVIDED CIRCUMFERENTIALLY INTO A PLURALITY OF ZONES OF EQUAL ANGULAR EXTENT, WITH THE TYPE BEING DISTRIBUTED AMONG SAID ZONES; SHAFT MEANS OPERABLE TO DISPLACE SAID DRUM ANGULARLY TO BRING A SELECTED ZONE INTO AN OPERATIVE PRINTING POSITION; A PLURALITY OF SELECTOR ARMS, EQUAL IN NUMBER TO SAID ZONES, EXTENDING RADIALLY FROM SAID SHAFT MEANS AT EQUAL ANGULAR SPACINGS CORRESPONDING TO THE ANGULAR EXTENTS OF SAID ZONES; AND EACH COORDINATED WITH A RESPECTIVE ZONE; A PLURALITY OF SELECTOR FORKS RECIPROCABLE TRANSVERSELY OF SAID SHAFT MEANS AND EACH ALIGNED WITH AND AT LEAST PARTIALLY EMBRACING A RESPECTIVE SELECTOR ARM; LOCKING SLIDE MEANS DISPOSED IN OPPOSITION TO SAID SELEECTOR FORKS AND RELATIVE TO SAID SHAFT MEANS; MEANS BIASING SAID LOCKING SLIDE MEANS TOWARDS SAID SHAFT MEANS AND INTO LOCKING ENGAGEMENT WITH THE SELECTOR ARM THEN IN THE LATCHING POSITION; EACH SELECTOR FORK, WHEN MOVED TOWARDS SAID SHAFT MEANS, DISPLACING SAID LOCKING SLIDE MEANS OUT OF SAID LOCKING ENGAGEMENT AND ENGAGING ITS ASSOCIATED SELECTOR ARM AND ROTATING IT, TOGETHER WITH SAID SHAFT MEANS, TO A LATCHING POSITION IN WHICH THE ASSOCIATED ZONE IS IN SAID OPERATIVE PRINTING POSITION; AND SELECTOR MEANS OPERABLE, WHEN ACTIVATED, TO MOVE A SELECTED SELECTOR FORK TOWARDS SAID SHAFT MEANS AND THEN TO RETRACT IT; EACH SELECTOR FORK, UPON SUCH RETRACTION, RELEASING SAID LOCKING SLIDE MEANS TO MOVE INTO SUCH LOCKING ENGAGE MENT. 